1. Field of the Invention
The present invention relates to usage control of content that is used as objects of a formed document.
2. Description of the Related Art
[Formed Document]
Document data in a format that represents a document in a combination of objects and forming information thereof (hereinafter referred to as a “formed document”) has been utilized in recent years. As used herein, “objects” refer to content items serving as components that constitute a document, that is, data items written in formats such as JPEG, PDF, Tiff and PostScript®. “Forming information” refers to data that specifies objects serving as components of a formed document, and in which the relationship between the objects and the formed document is written. When describing that “forming information specifies objects to be output” in the explanation given hereunder, it indicates that forming information specifies objects so that the objects are output as components.
For example, forming information specifies the coordinates and size of each object when outputting a formed document. A data file in which forming information is written (hereinafter referred to as a “layout file”) and data files of objects are archived and may be managed collectively or separately.
When forming information and objects are managed collectively, an output apparatus forms and outputs the objects in accordance with the forming information extracted from a formed document. On the other hand, when forming information and objects are managed separately, an output apparatus refers to object identifiers, such as URLs (uniform resource locators), that are written in the forming information, obtains objects, and forms and outputs the obtained objects based on the forming information.
Because each object is specified to be output in accordance with the forming information as described above, it is possible to create and edit document data without changing data of the objects.
A page description language (PDL) called personalized print markup language (PPML) is an example of a formed document. PPML describes forming information in an XML (extensible markup language) format and locates objects within a page in accordance with the forming information. With PPML, it is possible to specify objects internally (internal data) and/or externally (external data). Objects that are specified internally (hereinafter referred to as “internally specified objects”) are embedded within a layout file. Objects that are specified externally (hereinafter referred to as “externally specified objects”) are specified with identifiers such as URLs.
It goes without saying that data files of externally specified objects and a layout file are archived and may be managed collectively or separately. When externally specified objects and a layout file are managed collectively, an output apparatus forms and outputs the objects in accordance with the forming information of the layout file extracted from a formed document. On the other hand, when externally specified objects and a layout file are managed separately, an output apparatus refers to object identifiers, such as URLs, that are written in the forming information of the layout file, obtains objects, and forms and outputs the obtained objects based on the forming information.
[DRM]
Digital rights management (DRM) is a technology used to manage the copyrights of content as typified by digital data such as music, moving images and still images (see Japanese patent No. 3738020). With this DRM technology, a policy in which usage conditions for respective content are written is set, and the content can be used only when the policy is satisfied.
A policy is represented in a combination of a plurality of usage conditions, and each usage condition includes condition items and condition values. “Condition items” are items that are examined for the usage control of content. “Condition values” are criterion values that are used to determine acceptance or non-acceptance in the examinations. For example, when a condition item is “authorized user”, its condition value is a value that identifies a user A or user B. As the condition items, for example, the period of usage of content, the frequency of usage, usage location and so on can be used.
An example of an embodiment of this DRM technology will be described below. In the following explanations, content protected by DRM is referred to as “protected content”, and content that is not protected by DRM is (explicitly) referred to as “non-protected content”.
A content administrator (hereinafter referred to as an “administrator”) generates a license including a policy in which encrypted content obtained by encrypting content, a decryption key for decrypting the encrypted content, and usage conditions for the content are set, and distributes protected content in which meta information for obtaining the license is added to the encrypted content.
A person who obtained the protected content (hereinafter referred to as a “user”) requests the license using the meta information included in the protected content. The administrator issues the license to authorized users and users who have paid therefor.
A user who obtained the license uses the decryption key included in the license in accordance with the policy and consumes the protected content. As used herein, “the consumption of content” refers to a process in which data such as images and moving images is processed and output to a screen or in the form of printouts, a process in which content is copied or edited, and so on. To consume protected content, the usage environment (date and time of usage, user, etc.) of the content and the usage conditions written in the policy are examined to perform a policy evaluation for determining whether or not the protected content can be consumed.
According to another embodiment of the DRM, for example, the distribution of protected content is controlled such that the protected content is distributed only to terminals within a network as typified by a cell phone network, and the usage of the protected content by the terminals is controlled in accordance with the policy set in the protected content.
As described above, it is possible to control the usage of objects by protecting the objects with DRM. However, in the case of a formed document, objects are output in accordance with a layout written in the forming information, and thus output is possible by editing the forming information or changing the layout of the objects. Particularly when laying out and outputting a plurality of objects, a problem arises in that the layout differs significantly from the layout intended by the content administrator.